Optical transmission systems constitute the basic carrier for most telecommunication systems. Many optical transmission technologies are based on the principle of wavelength division multiplexing (WDM) or Dense WDM (DWDM), where the transmission channels are carried by optical signals over different wavelengths or different bands of wavelengths. The optical signals are initially modulated at the transmitter end of the optical network, propagated through the network via an optical link or fiber, and then detected at the receiver end. The optical signal may also be amplified before or after transmission to enhance performance, for example to compensate for attenuation or noise during transport. Erbium Doped Fiber Amplifiers (EDFAs) are one type of optical amplifiers that are commonly used in optical systems. However, EDFAs may also contribute noise in the optical signals, which needs to be accounted for.